Catalytic condensation of hydrocarbons



Filed July 3o, -1958 w, WQ

NSQ

s Mm w@ Patented Dec. 17, 12,940'

UNITED s'm'rtzs PATENT OFFEQE CATALYTIC CONDENSATION F HYDROCABBONS corporation ol.' Maine Application July 30, 1938, Serial N0. 222,138

, 7 Claims.

This invention relates to improvements in the catalytic condensation of normally gaseous hy' drocarbons to produce normally liquid hydrocarbons of gasoline boiling range.

lI refer more particularly are those saturated, or paraffin, and unsaturated, or olen. hydrocarbons containing four and less carbon atoms per 4molecule, methane, ethane, ethylene, propane. propylene, normal butane, isobutane, normal butylene and isobutylene. These hydrocarbons may be designated the C1, C2, C3 and C4. compounds, or collectively, C4 compounds. The normally liquid hydrocarbons to which I refer are those containing iive or six or more carbon atoms per molecule Within the boiling range of gasoline, which may be designated the Cs+ or Cs+ compounds.

The term catalytic condensation as applied to such hydrocarbons includes polymerization of unsaturates and alkylation or reaction between saturates and unsaturates. Catalytic polymerization of unsaturates has been proposed and practiced as a method of recovering motor 25 fuel gasoline of special value from less valuable hydrocarbon gas mixtures containing suflicient unsaturated compounds. Gas mixtures so processed have included gas mixtures from cracking operations containing as produced sufficient unsaturated oomponents and gas mixtures preliminarily processed catalytically or thermally to produce suicient unsaturated components by decomposition of saturated components. While some of these previous proposals and practices may have involved incidental alkylation, the conditions of operation have tended to suppress alkylation rather than promote this type of reaction. Alkylation and polymerization are, in some respects, inconsistent reactions and, consequently, it is not unnatural that those seeking to effect condensation by polymerization should have avoided conditions promoting alkylation.

In a co-pending application, Serial Number 204,736, led April 28, 1938, Patent No. 2,177,579, Roderick Donald Pinkerton and I disclose that by appropriate correlation of charging stock, temperature, pressure and catalyst, condensation with substantial alkylation may be effected either with concurrent polymerization or to the substantial exclusion of polymerization and that, by means of such correlation, gasoline-like hydrocarbon products superior in important respect to those of polymerization processes in which alkylation, if occurring at all, is merely incidental, may be produced from normally The normally gaseous hydrocarbons to which gaseous hydrocarbons including saturates and unsaturates.

According to this invention, an operation effecting condensation with substantial alkylation is combined in a special manner with an operation eiecting condensation with'incidental alkylation but with substantial concurrent polymerization to secure several advantages.

In carrying out one embodiment of the process of this invention, a`mixture of normally gaseous hydrocarbons including saturates and unsaturates is heated to a reaction temperature not exceeding the' critical temperature of the mixture under a pressure sumcient to maintain a substantial part of the mixture in liquid phase, the vapor phase is separated from the liquid phase under maintained pressure, the separated liquid phase is passed in contact with condensation catalyst at a temperature eiecting alkylation not exceeding the critical temperature of the mixture under maintained pressure suilicient to maintain the liquid phase, the separated vapor phase is passed in contact with a condensation catalyst, at a temperature effecting polymerization and the liquid products of both condensations are collected. The vapor phase catalyst contact is with advantage carried out under pressure lower than that of the liquid phase catalyst contact. Also, the vapor phase catalyst contact is with advantage carried out at a temperature higher than that of the liquid phase catalyst contact. Thus, the separated vapor phase may be further heated prior to the vapor phase catalyst contact. In carrying out another embodiment of the process of theinvention, a mixture of normally gaseous hydrocarbons including saturates and unsaturates is heated to a reaction temperature not exceeding the critical temperature of the mixture and is then passed in contact with a condensation. catalyst at a temperature effecting alkylation while under a pressure suiiicient to maintain it in liquid phase, the pressure on the mixture is then reduced, this pressure reduction being limitedv to preventsubstantial vaporization of hydrocarbons of gasoline boiling range, the resulting vapor phase is separated from the liquid phase, the separated vapor phase is passed in contact with a condensation catalyst at a temperature effecting polymerization and the liquid phase separated following the liquid phase catalyst contact and the liquid products of the second condensation are collected. In both embodiments of the process of my invention, a condensation primarily adapted to'eiect alkylation, although it a the calcined product porous. n n i may include polymerization, is combined with a condensation adapted to `eiiect polymerization in a manner promoting more complete reactionof those constituents ofwthe charge capable of reaction to produce liquid hydrocarbons of gasoline boiling range. Also, in both embodiments of the process oi the invention. appropriate condensation conditions are selectively applied to the varying `hydrocarbons t making up the material -being processed. The paramns are apparently c more reactive with; respect to alkylation as they decrease in molecular size. Thus, in the second embodiment, such relatively` morereactive paraiiins are maintained presentin maximumcon- `centration in both condensations.v At the same time, in the second embodiment, although the condensation reaction is carried on in the second condensation to promote complete reaction t and consequently high recovery, liquidproducts of the nrst condensation are withdrawn prior to the second condensation avoiding any tendency toward `continued condensation `oi these;`

products with possible production of material higher boiling lthanlgasoline.

Known condensation catalysts are generally v usetulincarryingout theprocessottheinvention." The phosphoric acid catalysts will nillustrate oner type oi catalyst which maybe employed toadt vantage. An appropriate phosphoric acid catai lyst may be prepareduior example, by mixing orthophosphoric acid or `pyrophosphoric ``acid t with an appropriate carrier, siliceous material such as kieselguhr or an aluminumsilicate for` example, and calcining the mixture at aNtem-winto the mixture prior to calcination to render The hydrocarbon mixture to be processedmay include. as supplied tothe `regions of,catalyst contact, an added gasoline `fraction substantially free from cracked constituents as described in a co-pending application oi Roderick DonaldPin- -priate for carrying out kerton.. BerialnNumber 204,737.` nled April `28. 1938.` n n n n Theacoompanying drawing illustrates, dla- Vgrammatically and conventionally, as anow diagram, `two arrangements of apparatus approure 1 andFigure 2, respectively. n

In the arrangement illustrated inlllgure `i, the

normally gaseoushydrocarbons including sat-` urates and unsaturates to be processedare forced v by means oi pump I through the heater I into the separator I( VIn-the heater l the hydrocar `bon` mixture `is heated torexample to 250' IIb-350 ll'. and inthe separator I a pressure `for exampleoi 50041000 poundsper square inch is maintained. The heater l may discharge ata"` pressure'approximatinrthat prevailing in'the t separator I. or thepressure may bereducedbetween the heaterzand the separator, by mesmo! valve Il, in which case the heater beo'per= atedunder a pressure sumcient to` prevent any i substantial vaporization therein. From the sepa- `ratorll, the separated liquid materialis discharged under through the `chamber l containing an appropriate condensation catalyst in which this material is contacted in liquid phase with the condensation catalyst `at the nrst and second `em-` i bodiments of the process of the invention in Fig.,

a temperature for example of 250 llt-350' F. and under a pressure approximating that prevailing in the separator l, pressure being maintained and regulated by means o! `valve l in conjunction with valve il or valve l and valve Il. The separated vaporised material Tis discharged from the separatori through the chamber I containing an appropriate condensation catalyst. This vaporised material may be further heated `ina supplementary heater llatterleaving the separator l and before entering thechamber l, and the pressure on this vaporised material maybe reduced as itpasses throhvalve I. In the chambers, this vaporised materiall is passed in contact with thecondensaticncatalystata temperature for example 01350' Pfofrfand under a pressure tor example or poundsper square inch. Thejnormally `liquid hydrocarbon products of both condensationsi are recovered conventionally from the hydrocarbon mixtures discharged from the liquidphasecontact and the vapor phase contact, respectively. valves If and Il..` n

Intbearrang'ementillustrated inflligure zthe normally `gaseous `hydrocarbons including saturatesandunsaturatestobeprocessed areforced by `means oi pump Il through the heater Maand ythe chamber i Il containing `au appropriate condensation catalystintothe separator Ii. `In the heater `Ihthe hydrocarbonmixtureis heated to a reaction temperature not exceeding the critical temperatureoi themixture, and, by means ot valve` il, a pressure sumcient `to maintain the mixture in liquid phaseisH maintained through the heater,` Il and :the chamber IL The tern-i perature in the; chamber it may approximate, ior

example, 200 F.350"F., and thepressure therea in `may approximate. `for example.` 500-1500 separating as a liquid in the separator Il is disn charged throusht'valveil. `f lhelvaporisefl mate- ,rialseparatingin `separator VII is;discharged under maintainedpressure-through chamber Il anapproprtate condensation catalyst and valve i The matexialdis-` chargedi'rom the separator Il tothe chamberl i! be passed through a supplemetary heater 2|. 'Ihe temperature maintained in the chamber Il may approximate `for example 350 1*.-650 l". and the pressure may `approximate for example 150450 pounds Der Square inch.l t n The Y normally liquid hydrocarbon products oi' both condensationslare recovered conventionally :i

fromw-'the i hydrocarbonnmixtureswfdischarged throughvalves l1 and 2l, the materials discharged through yalve 2l` havingpassed through boththe liquid,` contact andthe vapor phasecontact; a In bothembodiments of the process ot. the inventlon.` the liquid `'phase contact is with advanmentioned applicationierial Number 204,738,

A withthe further correlation ottemperature "and i pressure appropriate to the maintenance o! liquid t phase conditionswithin the regione! catalyst contact."` t n n a Bincelower temperatures tend to promote alkylation and tosuppress polymerization; whereas higher temperatures.` at least withinthe range to promote polymerization and to suppress alky-- lation and since in general higherv pressures tend to promote alkylation whereas lower pressures tend to promote polymerization, alkylation is promoted and polymerization ris suppressed although not necessarily excluded in the liquid phase catalyst contact of the combined operation of this invention and complete reaction, particularly of unsaturates, is promoted in the vapor phase catalyst contact of the combined'operation of the invention.

Thus, good recoveries of liquid products of gasoline boiling range are obtained and at the same time the superior properties characteristic of products of vcondensation by alkylation are re.

tained in improved measure.

I claim:

1. In the catalytic condensation of normally gaseous hydrocarbons including saturates` and unsaturates to pro'duce normally liquid hydrocarbons of gasoline boiling range, the improvement which comprises heating .the normally gaseous hydrocarbons to a reaction temperature of 200- 350 F. but not exceeding the critical temperature of the mixture under a pressure suilicient to maintain a substantial part of the mixture in liquid phase, separating vapor phase from liquid phase under maintained pressure, passing the separated liquid phase in contact with a condensation catalyst at a temperature eiecting alkylation but not exceeding the critical temperature of the mixture under maintained pressure upwards of 500 pounds per square inch andf-sucient to effect substantial alkylation and to maintain the liquid phase, passing the separated vapor phase in contact with a condensation catalyst at a temperature eiecting polymerization and colleeting the liquid products of both `of the resulting condensations. f

2. In the catalytic condensation of normally gaseous hydrocarbons including saturates and unsaturates to produce normally liquid hydrocarbons of gasoline boiling range, the improvement which comprises heating the normally gaseous hydrocarbons to a reactiontemperature 'of 200-350 F. but not exceeding the critical to maintain the liquid phase, passing the separated vapor phase in contact with a condensation catalyst at a temperature e'ecting polymerization and under pressure lower than that of the liquid phase contact, and collecting the liquid products of both of the resulting condensations.

3. In the catalytic condensation of normally gaseous hydrocarbons including saturates and unsaturates to produce normally liquid hydrocarbons of gasoline boiling range, the improvement which comprises heating the normally gaseous hydrocarbons to a reaction temperature of 200-350 F. but not exceeding the critical temperature of the mixture under a -pressure sufiicient to maintain a substantial'part of the mixture in liquid phase; separating vapor phase from liquid phase under maintained pressure.4

passing the separated liquid phase in contact with a condensation catalyst at a temperature effecting alkylation but not exceeding the criti .cal temperatureofthe mixture under maintained pressure upwards of 500 pounds per square inch and suicient to eect substantial alkylation and` 5 to maintain the liquid phase, vpassing the separated vaporphase in contact with a condensaf tion catalyst at` a temperature effecting poly--v merization higher than that of the liquid phase contact and under .a pressure lower than that of 10 the liquid phase contact, and collecting the liquid products of both of the resulting condensations.-

4. In the catalytic condensation of normally gaseous hydrocarbonsv including saturates and unsaturates to produce normally liquid hydrocarbons of gasoline boiling range, the improvement which comprises heating the normally gaseous hydrocarbons to a reaction temperature oi' 200-350 F. but not exceeding the critical temperature of the mixture under a pressure 20 sufficient to maintain a substantial part of the mixture in liquid phase, separating vapor phase from liquid phaseunder maintained pressure. passing the separated liquid phase in contact with a condensation catalyst under maintained-25 pressure upwards of 500 pounds per square inch and suicient to eiect substantial alkylation and to maintain the liquid phase,further heating the separated vapor phase and passing it in contact with acondensationcatalyst and collecting the 30 liquid products of both of the resulting condensations. l 'f i 5. In the catalytic condensation of normally gaseous hydrocarbons including saturates" and unsaturates to produce'V normally'liquid' hydrocarbons of gasoline boiling range, the` improvement; which comprises heating the normally gaseous hydrocarbons to a reaction temperature of V200350 F. but not exceeding lthe critical temperature of the mixture under a ypressure sufdcient to maintain a substantialpart of the mixture*` in liquid phase. separating vapor 'phase from` liquid phasev under maintained pressure, passingthe separated liquid'ph'ase 'incontact' with `a condensation catalyst ata temperature eiecting alkylation but not exceeding the critical temperature,y ofv the mixture under maintainedf pressure upwards of 500 pounds per square inch and.l suilcient to eiivect substantial alkylation and to maintain the liquid phase, further'heating the j' go separated vapor phase and passing it in contact with a condensation catalyst at a temperature `eiiecting polymerization and collecting the liquid products'of e both of the resulting condensations.

6. LIn the catalytic condensationof normally 55 gaseous hydrocarbons including saturates rand` unsaturates to produce normallyv liquid hydrocarbons of gasoline boiling range, the improve- 'ment which comprises heating the normally gaseous hydrocarbons to a reaction temperature of 20W-350 F.. but not exceeding the critical temperature of the mixture and passing it in contact withv a condensation catalyst while under a pressure upwards of '500 pounds persquare inch and sufficient to effect substantial alkylation and 05 to maintain it in liquid phase, reducing the pressure ofthe mixture and separating the resulting vapor phase from the liquid phase, this pressure vreduction being limited to prevent substantial vaporization of hydrocarbons of gasoline boiling range, passing the separated vapor phase in contact with a condensation catalyst at a temperature effecting polymerization and collecting the separated liquid phasev and the liquid products of the catalytic condensation of the vapor phase. l5

7. In the catalytic condensation ot normally lyst yat a temperature,eilecting` aikylation `'hilo gaseous hydrocarbons including saturates and. under a pressure upwardsoi 500 poundslpcr unsaturatesto produce'normally liquid hydrosquare incbmnd sumcientfto `eillsct substantial carbon: of gasoline boiling range, lthe improve-l alkylation` and to maintain laidcompmentinthe mentf which comprises heatinqtbe normnlly` anpor phasecanpo- 5 gaseous hydrocarbons to reaction nent from I nixture ofzow-350 l". but not exceeding` the critical` passim:` said vapor pbase componenti in contact temperature loi the mixture under a `pressure with a condensation catalyst at a sumcient to mpintain' a substantial part of the effecting polymerization and collecting the liquid mixture in liquid phase, vpassing the liquid phase products oi the resultinz condensatii'ms.` 10 component in contact with a condensation catai WILLIAM MENDIUS. 

